The purpose of this research program is to investigate the causes of hereditary neurological diseases, with the goal of developing effective treatments for these disorders. A genetic outreach program allows the identification and characterization of patients and families with hereditary neurological diseases. Specific research accomplishments in the past year include the following: (1) collaboration in the identification of genetic defects responsible for spinocerebellar ataxia types 15 and 20; (2) development of a collaborative genetic outreach program in Bamako, Mali; (3) collaboration in the identification and evaluation of candidate genes for Larsson-Linderholm syndrome, familial autoimmune myasthenia gravis, and X-linked spinal muscular atrophy.